The invention relates to a fail-safe radiation shutter, with filters and/or diaphragms which can be moved, for example rotated, into and out of the path of rays of an electromagnetic radiation or particle emitting device, especially a laser, by means of an electromagnetic adjusting or actuating mechanism.
For reasons of safety, so-called radiation shutters are required for the operation of a radiation emitting energy source, for example, a laser apparatus of class three and higher or an ion or electron beam mechanism, radiation intensity of which lies above a value which is hazardous to the human body. Such radiation shutters should insure that in the radiation intercepting position of the filters and/or diaphragms the emitted radiation is totally or partially absorbed or reflected and in any case lies below the respective danger threshold value.
A radiation shutter is known, for example, from the "VDI- Nachrichten" No. 26 of June 27, 1980, page 7. Such radiation shutters should not, however, be secured only against unauthorized access, but should also provide a minimum measure of intrinsic safety. Upon failure of single or several parts of the radiation shutter, for example, due to damage or material failure, the radiation shutter should continue to operate.